Unyango lokukhanya belukho ukususela oko izityalo nezilwanyana zazisesemhlabeni, njengoko sonke sizuza kwinqanaba elithile ekukhanyeni kwelanga kwendalo.
Ukukhanya kwe-UVB okuvela elangeni akupheleli nje ekudibaneni ne-cholesterol eluswini ukunceda ekwenzeni i-vitamin D3 (ngaloo ndlela inceda umzimba wonke), kodwa inxalenye ebomvu ye-spectrum yokukhanya okubonakalayo (600 – 1000nm) ikwasebenzisana ne-enzyme ephambili ye-metabolic kwi-mitochondria yeseli yethu, iphakamisa isivalo kumandla ethu okuvelisa amandla.
Unyango lokukhanya lwanamhlanje belukho ukususela ngasekupheleni kweminyaka yoo-1800, kungekudala emva kokuba umbane kunye nokukhanyisa ekhaya kwaqala ukusetyenziswa, xa uNiels Ryberg Finsen, ozelwe kwiziqithi zaseFaroe, wazama ukusebenzisa ukukhanya njengonyango lwezifo.
Kamva uFinsen waphumelela ibhaso likaNobel kwezonyango ngo-1903, unyaka omnye ngaphambi kokuba asweleke, ephumelela kakhulu ekunyangeni i-smallpox, i-lupus kunye nezinye izifo zesikhumba ngokukhanya okuqinileyo.
Unyango lokukhanya lwasekuqaleni lwalubandakanya ukusetyenziswa kwezibane zemveli ezikhanyayo, kwaye kwenziwe izifundo ezili-10,000 malunga nokukhanya kule nkulungwane yama-20. Izifundo ziqala kwiziphumo kwiimpethu, okanye iintaka, abafazi abakhulelweyo, amahashe nezinambuzane, iibhaktheriya, izityalo nokunye okuninzi. Uphuhliso lwamva nje yayikukungeniswa kwezixhobo ze-LED kunye neeleyiza.
Njengoko imibala emininzi yayifumaneka njengee-LED, kwaye ukusebenza kakuhle kobuchwepheshe kwaqala ukuphucuka, ii-LED zaba lolona khetho lufanelekileyo nolusebenzayo lonyango lokukhanya, kwaye zisemgangathweni weshishini namhlanje, kwaye ukusebenza kakuhle kusaphucuka.